Fifteen years ago, Alfred McKenzie began to wonder why he had never been promoted.

He had, after all, been operating presses at the Government Printing Office for more than 28 years, and by all accounts, was a valued worker. Some of the white pressmen he trained were moving up to supervisory positions. But McKenzie, like other black GPO employes, was passed over time and again.

"A lot of times I would complain about not being promoted," said McKenzie, who retired in 1973. "The supervisors would say, 'you're doing fine' and 'the possibility of promotion is good,' but I never got promoted."

Frustrated and bitter, McKenzie decided the time had come to challenge his bosses, sparking a legal odyssey that would last a decade and a half and grow into a major class-action victory involving hundreds of GPO pressmen and a $2.4 million settlement.

What began as one man's confrontation with the government ended recently when GPO officials distributed letters telling 362 black current and former press workers how much of the settlement they would be entitled to as compensation for pay they would have received if they had been promoted fairly.

Today, 50 of GPO's 85 mid- and upper-level pressmen are black. In 1973, one was. At the lowest level of skilled workers, 68 percent of workers are black, compared with 23 percent in 1973. (The percentage of unskilled workers at GPO who are black has not changed, remaining constant at more than 95 percent.)

"If it hadn't been for this suit, these changes wouldn't have occurred," said Jesse Hamilton, director of the Coalition for Minority Workers, a GPO organization that monitors racial issues. "Now people can at least have some hope that they can get a promotion if they work hard."

Under a court order, the system for evaluating workers has been changed to allow blacks a fair chance of promotion. Gone, McKenzie said, is the "old boy network" among white supervisors that kept him and other black pressmen at the lowest levels for decades.

The effects of the case range well beyond the GPO, lawyers for both sides said. The McKenzie case and several other landmark discrimination cases against the government over the last 20 years, they said, have generated a body of law that protects black federal employes from discrimination.

"It's hard to say that any given case has made a major impact across the government," said Douglas L. Parker, one of McKenzie's lawyers. "But when you look at a whole set of cases, in which his is an important one, a whole body of civil rights law has been established."

GPO's top lawyer handling the case admits the case has had far-reaching impact on the press division, but said the office was already headed toward making significant changes. "My belief is that the orders that the court issued probably accelerated some of the changes," said GPO deputy general counsel Drew Spaulding, "but I'm not certain that the numbers we have now wouldn't have come over a period of time -- maybe a longer period of time."

McKenzie's case began with an appeal to the Public Printer, the GPO equal employment opportunity office and a minority workers' organization, but with no results. Then he contacted the Washington Lawyers Committee for Civil Rights Under Law.

"It was obvious from his words and the unmistakable integrity of Mr. McKenzie that an enormous injustice was taking place," said Roderic V.O. Boggs, a committee attorney who handled the case.

On McKenzie's first day at the GPO, on the eve of World War II, he was told by white bosses that he was sitting in the wrong section of the cafeteria. After serving in the famous all-black aviation unit that became known as Tuskegee Squadron, he returned to the GPO as a press operator, a position he would hold for the next 28 years.

"A lot of times, people who had a lot of talent never got a chance to express it," McKenzie said. "A lot of talent was going untapped because people had the wrong color skin."

McKenzie filed suit in U.S. District Court here in May 1973. The case was declared a class action, and in January 1977, Judge Barrington D. Parker ruled that the GPO had discriminated against press-division blacks.

Four years later, Parker ordered the GPO to promote four blacks for every white and instructed black workers to create an organization to monitor implementation of the order. The government appealed the ruling, but in June 1982, the U.S. Court of Appeals here upheld the decision. The GPO and lawyers for the pressmen agreed to the settlement last year, and the district court approved the agreement in May.

McKenzie never got a promotion, but said the suit was well worth the effort.

"I never had any idea it would turn out as large as it did," McKenzie said. "But as things started to develop I saw the chance to really help others. What made it worth the effort was the changes that have been made at GPO that are helping the workers there now."